Getting Abmob to work

I have been trying to add MobAds to my mobile game but I have been unsuccessful, I have copied the numbers over and placed them into the project files and also added a blueprint to display the ads on a button press and when the level starts but this still doesn’t work when I launch it on my android or publish via google play.

Can anyone help, I’ve looked for documentation but it is telling me what I have already done. I have added photos of the blueprints and mob ad details.